Telephone



(Moden 0.11. BUELL. A. Telephones. No. 232,675. Patented Sept. 28, i880.

Unirse STATES Arnim Price@ CHARLES E. BUELL, CF NEW HAVEN, CONNECTICUT.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 232,675, datedSeptember 28, 1880,

Application filed July 2, 1880. (Model.)

To all whom it may concern Be it known 4that I, CHARLES E. BUELL, of NewHaven, in the county of New Haven and State of Connecticut,haveinventeda new Improvementin Telephones; and I do hereby declare the following,when taken in connection with the accompanying drawings andthe lettersof reference marked thereon, to be a full, clear, and exact descriptionof the same, and which said drawings constitute part of thisspecification, and represent7 in- Figure l, a plan view of theinteriorof the telephone and transmitter in connection; Fig. 2, a sectional viewof the telephone.

This invention relates to telephones which are adapted to thereproduction of sonorous waves or vibrations by means of electricalimpulses traversing a conducting-circuit.

The object of my invention is to increase the sensitiveness ofreceiving-telephones; and a further object of my invention is toconstruct and arrange receiving-telephones in such a manner as to affordtheir double use as the induction apparatus of a battery-transmitter;and my invention consists in the construction hereinafter described, andparticularly recited in the claims.

Although the accompanying drawings represent my improvements as groupedin one instrument, it is obvious that parts may be used in telephoneswhich differ in the detail of their construction from the one shown.

A is the diaphragm in contact with the end of the core of each of the.electro-magnets l 2 3 4, the contact being at or near the edge of thediaphragm.

The actuating-magnet ofthe telephone is in the form of aninduction-coil, and is an electromagnet. The soft-iron core aiscontained within a helix, b, of low resistance, which, when charged asthe primary coil of the inductorium, acts to magnetize the core a. Theelectro-magnet thus formed is surrounded by a helix, C,

of ne insulated wire of suit-able resistance, and this inclosing-helixserves as the inducing-helix of a` receiving-telephone and as thesecondary helix of an induction-coil 'of a variable transmitter.

The primarylhelix b forms part of a local circuit, in which is includedthe transmitter T of any of the ordinary carbon or other transmittersdepending for their operation upon variable resistance. Theelectro-magnets l 2 3 4 are also included in the same local circuit, andconnected in relation to the primary coil b, so as to cause the cores ofthe several electro-magnets at the edge of the diaphragm A to be of anopposite magnetic polarity from that of the core a of theinducing-magnet C.

The secondary coil c forms part of the main circuit. These parts arearranged in a case which is provided witha mouth-piece, lB, and ahandle, lz, through which the iiexible conductors for main and localcircuits may pass to connect with their respective helices.

The contact of the light iron diaphragm with the mass ot" iron of thecores 1 2 3 4: contributes to its inductive mass without adding to itsweight or impeding its vibrations, and when these cores are charged inan opposite polarity to the core of the inducing-magnet the dia` phragmis rendered responsive to the slightest inductive eli'eot exertedthrough the varying magnetic condition of the core a of the inductoriumC.

The employmentot'electro-magnets, as placed at the outer edge of atelephone-armature wholly separated from the central inducingmagnet andincluded in the same normallyf closed electric circuit with the primaryhelices of the inducing-magnet, and producing oppo- -site magneticpolarity, as shown, results in the following-named advantages: Shortenedmagnetic cores can be used, which will respond more rapidly tovariations of magnetic induction, and by being charged by an oppositepolarity in the saine normally-closed circuit with the inducing-magnetthey serve to hasten the dissipation of the retained magnetism, which ispresent in the inducing-magnet when its closed circuits tension isvaried, a dissipation of retained magnetism, which otherwise isprolonged in its cessation and an obstacle to distinctness ofarticulation, and.

the employment of an induction apparatus as the actuating-magnet of areceiving-telephone dispenses with the inducing-coil in the combinationheretofore used with variable transmitters employing local batteries,and with advantageous results.

l claiml. The combination, with the armature of a 1o magnet of atelephone, of one or more electromagnets included in the samenormally-Closed' electric eireuit therewith, and arranged to producesecondary pulsations in an opposite direction thereto, when the tensionof the ineluding eireuit is varied, and With means for Varying theeircuits tension, as shown.

CHARLES E. BUELL. Witnesses:

JOHN E. EARLE, J. H. SHUMWAY.

